根据jquery中填充的字段数计算并自动更新百分比

I have a form with 5 fields

我有一个包含5个字段的表单

    <form>
   First name: <input type="text" name="firstname" required><br>
   Last name: <input type="text" name="lastname" required>
   Age: <input type="text" name="age" required>
   Gender: <input type="text" name="gender" required>
   City: <input type="text" name="city" required>
   Locality: <input type="text" name="locality">
   Address: <input type="text" name="address">
   </form>